Question

Wheat flour is separated from wheat bran by the method of;
(A) Handpicking
(B) Sieving
(C) Winnowing
(D) Filtration

Answer 1

Hint: Mixtures of solution, liquids and solids or intermixing of various states of compounds can be separated by the different techniques. These separation methods depend on the size of particles and as well as state of particles. Simple handling method. Heavier grain particles are separated.

Complete step by step answer:
It is advisable to sieve the wheat flour to separate the bran. This is because of the difference in the size of wheat flour and its bran. Comparing the size, bran is bigger than the wheat flour which can easily separate out by the sieve.
Sieving is the method of separation of particles from a mixture based on the difference in size of particles. It is responsible for retaining the larger particles. Sieve plates are used for the separation of coarse particles from the finer particles. These sieve plates will allow only the fine flour particles to pass through the holes of the sieve plate. Bigger impurities are unable to pass through it so they may remain in the sieve.
The sample is subjected to horizontal or vertical motion during sieving. This causes a movement between the particles and the sieve.
Sieve plates have perforated bottoms which will allow particles of a specific size to pass through it. Their size can vary from one place to another depending on its application.
Handpicking will require a lot of time to separate out the brand. So, it is better to sieve than pick by hand to remove the bran.
Sieving is a traditional method which doesn’t require much of our skills. It takes less time. It is used in flour mills or building sites.

So, the correct answer is Option B.

Additional information:
Wheat bran is one of the three layers of the wheat kernel. It is a time saving method. There are different types of sieving methods which are used to separate different sizes of particles. It works only with the dry particles.

Note: Smaller sized particles can be easily separated. It is not applicable for the fibre products. The major disadvantage of this method is the material may roll on the surface of the sieve and fibrous material tends to form “ball”. If Particle size is too small it is passed through a sieve.